lindequist



- June 28, 1927. 1,634,249

s. LINDEQUIST EXPLOSION ENGINE WITH FOUR OR MORE WORKING CYLINDERS Filed March 59. 1925 7 Sheets-Sheet 1 2 1 2 June 9 s. LINDEQUIST EXPLOSIQN ENGINE WITH FOUR OR MORE WGRKING CYLINDERS 7 Sheets-Sheet 2 Filed March 30. 1925 June 28,

S. LINDEQUIST EXPLOSION ENGINE WITH FOUR OR MORE WORKING CYLINDERS Filed March 30, 1925 a $5; f [,4 14A '7 Sheets-Sheet 3 June 28, 1927. 1,634,249

S. LINDEQUEST EXPLOSION ENGINE WITH FGUR OR MORE WORKING CYLINDERS Filed March 30, 1925 7 Sheets-Sheet 4 2 192 June 7 s. LINDEQUIST EXPLOSION ENGINE WITH FOUR OR MORE WORKING CYLINDERS Filed March 50, 1925 7 Sheets-Sheet 5 June 28 1927.

I 5. LINDEQUIST EXPLOSION ENGINE WITH FOUR OR MORE WORKING CYLINDERS Filed March 50. 1925 7 Sheets-Sheet 6 1,634,249 June 28, 1927. S. UNDEQUIST EXPLOSION ENGINE WITH FOUR OR MORE. WORKING CYLINDERS Filed March 0. 1925 7 Sheets-Sheet 7 Patented June 28, 1927.

PATENT OFFICE.

SVEN LINDEQUIST,OF WILMERSDORF, NEAR BERLIN, GERMANY.

EXPLOSION ENGINE WITH FOUR OR MORE WORKING CYLINDERS.

Application filed March so, 1925, Serial This invention relates to an explosion engine with four or more working cylinders, closed at both ends and working at one end as a compressor, and with a crosshead constrncted to serve as a second compressor piston.

According tothe invention the compressor charges from the compressor end of the working cylinder as well as from the crosshead cylinder are fed to a conduit which is common for the inlet valves of all the working cylinders so that, for instance in four stroke cycle engines, four compressor charges are at disposal for each working stroke. It has become known to construct explosion engines to work like compressor engines by closing the cylinders at both ends and by making the bottom part of the cylinder serve as compressor. In engines of this type, working in a four stroke cycle, two compressor charges are at disposal for each working cylinder charge. This means, the losses having been taken into considera tion, an excessive charging or pracompression of 190% of the working cylinder Volume.

The invention serves for special purposes, for instance for high altitude flying machine motors or in general for motors which require a considerable over charging or a considerable compression of the air volume admitted. The object of the invention is realized by the simplest means and with only a slight increase in engine weight.

The effect maybe further improved by arranging, besides the working piston which works as a compressor piston and besides the crosshcad piston working in a compressor cylinder, a third piston in a compression cylinder, all compression spaces working, as stated above, on a common conduit leading to the inlet valves of theworking cylinders. In this case eight compressor charges are at disposal for each working stroke in a four cylinder engine. If at each side of a common working space an aggregate of three pistons and of corresponding compressor spaces is arranged, and if all compressor spaces work on a common conduit leading to the inlet valves for the working spaces the possibility of pie-compressing the working space charge is still further increased.

The piston arranged between the cross- ,iead piston and the working pistons may be No. 19,487, and in Germany May 1, 1923.

mounted unpacked in the corresponding cylinder, in order to reduce the friction, as the compressor air flowing back between the piston and cylinder-wall, especially at high speed, is of no consideration in comparison with the other losses.

If the volume of the pipe conduits is made sufiiciently small and if every two working pistons with corresponding compressor pistons work in opposite directions the peaks of the pressure curves in the pressure pipe connecting the compressors with the inlet valves of the working spaces arrive, independently of an eventual variation of the speed with excessive charging, at the correct moment at the inlet valve of the working space. In order that the opening time of the working space inlet valve may be adapted to the time at which the pressure peaks arrive, the con trol of the valve may be made adjustable, for instance by controlling each valve by two cam shafts which are arranged in such a manner that the position of the curves of both shafts can be varied with regard to one another.

The engine cylinders which contain the above mentioned piston aggregates are preferably arranged tangentially to a circle and the crank shafts are then situated in the points of intersection of the axes of the cylinder aggregates. On one crank shaft work always pistons of two or more cylinder aggregates, the number depending upon the number of cylinders arranged in a row in each tangential plane. On the crank shafts gear wheels may be keyed which mesh with a gear wheel on the main shaft to be driven.

he degree of excess charging, i. c. of the pie-compression of the charge, may be regulated by suitable means, for instance by directly connecting the compression spaces of at least two cylinders, working in opposite directions to each other by a conduit or regulating element. If this regulating element is fully opened the two compressors communicating through the connecting conduit have no eii'ect on the pressure conduit. The air which has been previously suckedin is merely pushed over from one compressor cylinder into the other compressor cylinder.

If the regulating element shuts oil the cross section of the conduit more or less, the discharge from the compressor into the pressure conduit is more or less increased. The

discharge of compressed air can thusbe regulated'wlthout any loss of Work from 1 '0 to the maximum. The cl arging'ot' -th'e 7 Working space can therefore be done through V the compressors even at the lowest volume of compressed air, the efiiciencyot the engine being not essentially reduced. The tormation of a pressure below atmospheric in the worlnng conduit or sin the adinission'conduit can therefore, if it should be desired, be avoided under any conditions. is Thecon necting conduit between the compressors, mentioned above, may be situated in' the cylindersydt might, however, be arranged outsidethecylindersand instead of one such conduit several conduits i'i iaybe employed.

-- suitable arrangement.

compressors is reduced.

Besides .thi's connecting conduit between two oompressorspaces Working in opposite directions a device may be used by means of wh ch the nlet openings of the compressors can .be throttledjso that,,accor,ding to the degree of throttling, the discharge from the The-charge at the adinissionior exhaustof the compressor may further bealloived to escape into the atmos phere. s I V The regulating element the connecting conduitlcan be controlled automaticallyby theinner pressure of the compressor pressure pipe by makinggthe inner pressure for instance act uponapiston adapted to be moved in oppositionto a spring or upon any other 'In order toenable that a ,regulationof the speed or any adjusting of the average compression pressure may be carried out through'the intermediary of the connecting conduit, a regulating element to be controlled by hand may be arranged in the connecting conduit, besides the regulating element auto maticallycontrolled by the inner pressure of the compressor pressure conduit. For hig'l'i altitude flying mach1ne eng nes a control element may be further arranged in the con-- necting conduit, the controlof which element 7 depends on the atmospheric pressure, or the regulating element for the distribution dependent on the inner pressure of the compressor (pressure conduit may be rendered reversible so that its operation is made dependout on the pressure ofthe outer air.

it is further advisable, to mount in the connecting conduit, between the compressedair pipe andthe control element for the regulatingje'lemcnt,a'check valve the spring of which is regulated so that it remains open at sor spaces, which are arranged one behind the other in axial direction, are best 'con-" trolled by rotary valves common for every tWo compression spaces, the conduits'from the compressors to the rotary Valves being .arranged ,one at the side of itheiothen'; When the speed of the rotary valve-shaft is half I or one quarter of the-speed of the engine shaft the shaft of the rotary valves may serve at the same time as a cam shaft for th valves not the working cylinders; Y i

, pre-con'ipression o't-the ases, ,which according to theinve n ti-on can to a high degree,'can not only beutiliZed, as stated above, to increase the speed and to maintain the compression uniform in high altitude engines, but, at a certain manner of operation, the invent on permitsof manufactur ng by the process of casting metal under pressure even those building elements,

e increased as forin'stance' cylinders, pistons, cylinder covers and the like, which are submitted to The diameter of the bore of the I lii h stress. cylinder is made considerably greater than the stroke, and, according to the invention,

compressed air or gas mixture is admitted 1 to the Working space in regulating the ad mission pressure' in accordance with the speed. The regulating is effected in sucha.

Vman'ner, that a full charge is "obtained ata 10W compression pressure in the Working cylinder. xThis special construction ofjthe' engine has for its objectto reduce the stress on the elements made by the process of casting metal under pressure.

Up to the present, so taras the process for casting metal under pressure was applied at all the manufacturing of engine ele nients,only such building elements were pro duced by this process as'were not exposed to high stress, as for instance the crank shaft bearings. The manufacturing of parts, ex posed to high stress, as for instance the cylinder, appeared impossible as the resisting capability of the metal parts cast, under pres sure was too low to Withstand the stresses .ivhich occur in the normally Working engines. By the above stated special construe engine the stresses" tion' and operation of the are considerably reduced n The excessive dimensioning of motors was hitherto used only for increasing the eflicien'cyof the motor beyondthe normal effciency. According to; the invention an excessive dimensioning is used preserving the normal efliciency so that'it is ossibley'to.

maintain in the \vorking cylinder ower average explosion pressure than is possible with normally dimensioned cylinders. By this reduction of the explosion pressure the loading of the material is reduced atthesame time the piston stroke which is comparatively short in excessively dimensioned inotorspen f i i otmanaging it with slow acceler atmg forces. 'Whena construction of motor and an operating method as stated are employed the process of casting metal under pressure may be used also for the highly loaded engine elements without any danger of destruction of these elements by the loads which occur in service.

The invention permits further to obtain, in a comparatively simple manner, reversibility of the motor. With this object in view the admission and exhaust conduits leading to and from the compression spaces may be fitted with reversing elements, for instance valves, so that the air pressure of an air reservoir capable of being filled by the con'ipressors can be made to influence the compressor pistons, the ignition in the work ing space of the motor cylinder being rendered at the same time inoperative, whereby reversing ot the motor is obtained. By arranging reversing elements in the admission conduit to the working spaces of the cylinder the use of gasair mixture compressed by the cylinder compressor may be rendered possible.

An embodiment of the invention is shown, by ay of example, in the accompanying drawings in which Fig. '1 shows an end'view, partly in longitudinal section of an engine having tangentially arranged cylinder aggregates.

Fig. 1 is an enlarged section of a. portion of Fig. 1.

Fig. 2 is a longitudinal section on line 1I-II of Fig. 1.

Fig. 3 shows diagrammatically the regulating device on the engine for the pressure in the compressor pressure'pipe.

Figs. l to 7 illustrate diagrammatically the reversing mechanism on the engine, Fig. 4: showing the several elements of the mechanism in the position which corresponds to forward rotation of the engine without ever loading, Fig. 5 showing themin the position corresponding with forward rotation with over loading, Fig. 6 corresponding to back ward rotation without over loading and Fig. 7 corresponding to backward rotation with over loading.

Referring to Figs. 1 and 2 of the drawings sir; cy der aggregates a, each aggregate comprising four cylinders, are tangentially arranged so that they are mounted concentrically around a common centre. Every two cylinder aggregates have a common crank case Z) and a common crank shaft 0 accommodated in the same.

In each of the cylinders of the aggregates two working pistons (Z are arranged so that the pistons of each cylinder work in opposite directions.

Compressor pistons g are mounted on the piston rods at the off sides of partitions f and also the crosshead pistons which are separated from the compressor pistons by a partition f the partition 7",, and between this partition f and the piston 9 serve as compressor spaces. The inlet ports of the compressor spaces are controlled by valves in which are operated each by two cam shatts 7L cam shafts are coupled with their driving These mechanism in such a manner that their positions with regardto one another and with regard to the driving mechanism can be changed. The simplest means of coupling would be the drawing along of the ram shait' by friction. For the same purpose arrangements oi epicyclic gears may be employed. The discharge side ot the compressors is controlled by rotary slide'valves k which are'driven at or M; of the speed of the motorshaft and can serve at the same time for operating the inlet or admission valves 2' for the working space. The cam shafts 2' tor the operation of these admission valves 2' for the working space has been shown, for clearness sake, directly underneath the valve rod.

The outlet ports h for every two adjacent compressors, are arranged side by side so that the two compressors may be controlled by different compartments of the same rotary slide valve. Owing to the use of the rotary slide valve very long and narrow cylinder inlet and outlet slots can be used whereby the cylinder length and the height of the pistons are considerably reduced.

Farther down, with reference to Figs. 4A? it will be described how the channels trom the outlet compressor ports to the working space admission valves are controlled.

On the crank shafts 0 gear wheels 71; are keyed (Fig. 2). Intermediate gears 71:, con nect gear wheels Ii, with a central toothed wheel Z keyed upon the shaft m. This shaft 972 may serve for instance as a propeller axle. The shaft m is journalled in a hearing it fixed on the end face of the body formed by the cylinder aggregates.

The gear wheels which serve for drivingthe cam shafts 2' and the rotary slide valves 7% are driven from the intermediate wheels 75,. In the form of construction, shown by way of example, all pistons are of similan diameter. The diameters of the several pie tons might. of course, be different when the cylinders are staged accordingly. Several of such staged pistons might be arranged the one behind the other so that they work as differential compressors. Differential p s ors are for instance employed for Til the production of injection 'air for fuel when ciple. p v

. The conduits leading from the compressor the engine operatesnpon the Dieselpriir 'outlet valves 'to the working space inlet valves,-are, as already stated, as short and narrow'as possible. Ithas been found that, when'the shortest fay is selected for the tubular conduits, they have, preferably, a diameter equal to of the. cylinder bore in large size engines, ,4 in medium sired enginesand to in small size engines.

For theabove mentioned regulating of the inlet valves as regards adaptation to the time of arrival of the pressure peaks, it is,

. sufiicient if, for instance by arranging two cam shafts 2 tor each valve, the opening time of the, valve 2'. is'variable'to the extent ofabout with regard to. opening time. y I

' 'Theregulatability of the working space t e normal inlet valves permits of allowing under any c.ondit1ons,. even when the cond tions of .working are variable, sufficient time for the filling ot' the Working space.

The adjusting of the cams for the purose of re ulation ma either be eil'eoted'so that the valve opens earlier than at normal adjustment or that it closes later. 'Theentire opening time may remain uniform or be lengthened.

In order admitted to thework-ing cylinder the cylinder bottoms f and f have a passage 39,

as shown in Figs. 1 and 1 through which a tubular slide valve 18 guided. Passages arranged transversely to the passage 7) connect the compressor spaces with the pa.-'

sage p and consequently with one another as soon as the tubular slide valve in the passage 79 uncovers the orifices of the passages 39 A part of thecompressor charge is then pushed over from the ,one compressor into the other through the passages 19 more ogt'.

the compressor charge of one compressor flowing, over into the ad acent compressor space as the passages 79 are opened wider.

The quantity of compressed air delivered by the compressors into the pressure pipe 171. is varied accordingly. .The amountot compressed air can further be varied by adj'usting the two cams h belong ng to one and the same compressor inlet valve relatively to each other, so thatthe inlet valve opens fora longer or shorter tune. The longer it is open-the more air can be sucked in, the shorter it is open the less air is sucked in. v

into th inf w end it merely necessary that the engine be con-f to regulate the quantity of air m xt re of omp essed-ai rises Withou he in ermed ry 1f the c mpr so fl ws In "this case it 1s tru ted f om th beg nn ng s that; t th lowest efiiciency which jisto beconsidered c nom al, the ng ne Works with min -mum ,p

compression in the workingeylinder space,

h h comp e s n co esp nd t 1 rest--' efiioiency. lVhen selecting'fthis lowest aver:

age compress on pressure of the working to be taken into consideration that there must always be sufficient charge for the engine at'disposal in the charging elements so that the highest calculated speed can be obtained at any-desired over-charge without losses of the filling of the working cylinder. Inlorder to increase thespeecl the 7 pressure in the over flow pipe is progres- SlVQly increased.

, In this manner any pressure below the atmospheric is avoided in the overflow pipe except during the starting period at which.

the engine works across the'compressors as suction engine. Thisstartmg period s below" the lowest etficiency to be considered.

' cylinders prior to the construction, it-has Y Engines may evidentlybe built for the highest admissible average compression pressure and which up to thispressure work with a lower pressure than the atmospheric.

peaks, and in order to obtain smallsized valves or short valve strokesandthe like, higher speeds n the overflow. p pes are desir-able and, with this object in vView, higher pressures. The first mentioned method is" therefore the most advantageous for high speed engines; the'two methods might eventually be combined.

In order tocontrol, by means'of the pressure in the compressor pressure pipe, the

tubular slide valve in the passage 1), which might be constructedlilre a cock, this compressor pressure. pipe k may be connected, as shown in Fig.6, bymeans of a branch pipe 8 with a control ,devicet which autorangedin the passage p. I fins CODtlOl'ClQVlCtt cons sts of :1. cylinder. 1 wh ch a p ston 1s movably ar Owing to. the retardation of the pressure matically acts upon the control element arranged, exposed to theaetion o fpa spring'w.

The pressure in the pressure conduit h; acts upon the topside of this piston and has the tendency to press the piston downward against the action of the spring to. The

spring is" regulated so that at ndrmal' pressure in the pressure conduit ,gno movement ta e pla e, w en he n rma P e ure is esceeded the piston. ispressed'downwardso that it mak s the lever 3 oscillate lfaround t r e P0 nt' t 1r 11 1 h t rm a y of the piston rod 90.. The lever transmits it m vem n y means at a li k 11m h control lever of the regulating element" \Vhen the piston 10 is in the normal or highest position the regulating element '0 is closed. As soon as the piston it begins to descend the regulating element opens. By regulating the bressure otthe s ring, the adjusting screw of which, not sliown, co-operates with a scale, also not shown, the engine can be adjusted to the desired everage' compression pressure. As soon as this average compression pressure is exceeded the valve opens and reestablishes the desired average compression pressure.

In order to make the mechanism shown in Fig. 3 work, it necessary, in dependency on the atmospheric pressure, the pipe 8 may be arranged so that it can be shut oft by a cook, a second pipe 8, being provided at the bottom end of cylinder 15'. This pipe 8 is also adapted to be shut off by a cock or by a similar device. When the pipe 8 is shut oli' and the pipe 8, opened a constant air pressure exists in the upper part of the cylinder Z while in the bottom part of this cylinder the pressure varies in accordance with the atmospheric pressure. As soon as this pressure sinks below a predetermined degree the pressure in the top part of the cylinder t pushes the piston u downwards and operates thus the regulating element 1",.

Instead of the means shown any other pressure relay of known type may be employed to control the regulating element 7 in dependency on the atmospheric pressure. The control must always be effected in such a manner that at decreasing pres sure of the atmosphere the regulating element is moved in the d 'ection to close the passages 79, so that with the decrease of the suction pressure the compressor eii'iciency increases and so that,.consequently, the pressure in the compressor pressure pipe is maintained uniform.

A check valve in the intermediate conduit 8 protects the regulating mechanism against the propagation of excessive pressures at the backflow of pressure from the working space into the compre sor pressure pipe.

When the above described automatically controlled regulating element is used it is also necessary that this regulating element 9 be capable of being controlled by hand, for instance so that to the control lever a, different positions may be given with regards to the pull rod r which connects the control lever 1', with the lever 21. A second regulating element, adapted to be operated by hand, might however be arranged at the side of the regulating element '2) or concentrically in the regulating element which is adapted to be controlled onlyautomatically.

The hand-controlled element serves then to produce variations of the speed of the engine by its displacements.

The hand-controlled regulating element is normally in the open position.- The automatically controlled regulating element, however, is normally, when the engine is working at normal etiiciency, only slightly open. By partial or complete closing of the handcontrolled regulating element the pressure produced by the compressors is consequently rease l so that the engine adopts a higher speed. By the automatic control of the pressure in the compressor pressure pipe the following advantages, amongst others, are obtained.

With the aid of the same, engines of much lower average compression pressure may be built than at present.

By the control of the regulating element by hand the etliciency (volume-capacity) can be altered without any alteration of the structure of the pressure curve in the compressor pressure pipe.

The atmospheric regulation of altitudespeed does away at the same time automatically with the sucking in losses of the compressors increasing with the higher speed.

In order to be able to reverse the engine at will to forward rotation with or without over loading and to backward rotation with or without over loading the connection of the compressor spaces with the working spaces of the engine is realized, in the form of construction illustrated by way of example, as diagrammatically shown in Figs. 44'. In order to avoid complication of the illustration the diagram is shown only for one compressor space of each cylinder, four cylinders being represented. It is obvious that the other compressors arranged in each cylinder of the engine do not alter the connection as all compressors of one cylinder communicate with one and the same pressure pipe 7L4.

According to the diagram shown in the Figs. 4-7 the engine cylinders A A A A, have each working spaces B and compressor spaces C. The pistons of every two cylinders, viz of cylinders A, and A and ofA and A, work in opposite directions. This is expressed in the drawing by showing the piston rods connected. For all cylinders one compressed air space D is arranged which, during the time the working cylinders work with uncompressed air, is charged by the compressors C. This space for compressed air D can be utilized, according to the invention, in connection with several valves, for reversing the engine.

For forward rotation without over-loading (Fig. i) the pipe Z supplies to the compressor cylinder the suction air directly from the atmosphere. Vith this object in view the valve E is adjusted for communication of pipe Z to pipe 2. The pipe 2 leads to the valve F which, in the position shown in Fig. 4, connects the pipe 2 with the pipe 8 which itself is connected by valve G with the compressor-intake pipe 4.

' scribed.

The'coinp ressor outletpipefi leads through valve H to' the pipe 6. The pipe 6 leads through valve Ifto'thepipe 7 which leads through valve K into the reservoir D for compressed air. At the orifice ofthe' conduit 13,, leading into the compressed air reservoir D, a checl; valve R, is arranged which can be temporarily maintained in open position with the aid of a niechanisin which will be hereinafter described and for a purpose which will be also hereinafter de- The' same 1 arrangement is used in connection with a second check valve R in the oriiice of a conduit 13' in the coinpressed air res'ervoii-D'.

The compressed air is therefore fed from V tliecoinpre'ssor to the compressed air reser voii.

The compression spaces of all other compressors operate in a similar manner.

The air is supplied to the Working cylinder from the carburettor through conduit 8, valve F, conduit.9, valve 1', conduit 10,

- valve H, conduit 11, valve G and conduit 12,

the exhaust port A oithe working cylinder ooininunic'atii'ig directly with the atinos- 7 v phere.

I At toi'w-ard rotation with over-loading (Fig. 5) the valve F is adjusted to'the p'osr tion of passage from the pipe 8, coining fron'i the carburettor, to the pipe 4 which leads tl irou'gl'i the valve G to the compressor inlet S, so that the compressor sucks in air saturated with fuel. The valve I is in the position: of passage fro nipip'e 6 to pipe 10.

The fuel and air mixture is conducted through the compressor outletipipe 5,va-lve Efpipe 6, valve 1, pipe lO,,valve H, pipe 11, valve G, pipe 12 to the working cylinder.

The combustion gases-flow out of the work i'iig cylinder through the exhaust port A.

For. reversing froin forward rotation without ovei-'-loading to forward rotation with over-loading it is merely necessary to rotate the valves F and I through 45.

' Backward rotation without ov'ei' loadinfg isobtaiiied by giving to the valves E and K the positions shown in Fig. 6, i. e. these valves are rotated from the position for forward rotation without over-loading, through 45 and 180 respectively so that the conduit 2 is no longer connected with the pipe 1 communicatingwith the atnio'spherebut the pipe 13, whichcommunicates with the coinpressed-air reservoir D, the pipe 7 being no longer connected withthe pipe 13;, which leads'to tl'ieco npressed-air' reservoir D but with the pipe 18 communicating with the atmosphere. Simultaneously withth is reversing the switch S is brought from the position shown in Fig. Loin which'the elec trio current controlledby the switch has lifted the compressed air valve R, by means of a magnet, into'the position shownin'Fig.

6. In this position the electric'currentlifts ream The saine current acts, the switch S being a voir 1)" through the conduit 13 through valve E, conduit F, conduit- 3, valve G, conduits to the compressor; The p ston are shown at '14, 15

the V is'at. first retarded by the action of the coinpressed air and stopped whereupon it' drives the crank shaft in the opposite direction,

'lheflsparking plugs are switched out, as mentioned above, until the "reversalbegins,

to be switched ii -again by' hand" after the backward rotation has started. i In the process for initiating the reversal the con'ipi'essed air flows out oftl'ie conipr'esso'r tl'iiou-gh the outflow pipe 5 "andescapes through valve H, conduit 6, valve 1, conduit 7, valve K and pipe 18 into theatinosphere.

I Simultaneously with the switching-in of \the sparking plugs, which is efle'cted by bringing the switch S from the "position shown Fig: 6 into the position shown in Fig. 4,- the valve R is 'leftjto itself in consequen'ceof the switcliing off of thejcurrent alldlt is consequently closed by the action of its spring. It acts now as check valve. The air-flow throughthe 'coinpi'essors is now, the air pressure from reservoir" D being no longer capable to act effectively upon the compressor, as follows? pipe 18; valve R,

jail) P p 7,; va-1ve I", pipe 6, valve H, pipex5,

compressor,pipee, valve G, pipe 3, valve F, pipe 2-,- valve' E, pipe 13,- compressed air reservoir D. r v i- The working space B of the engine,'which is" operative at the reversahsucks theifuel and a l1 mixture in through the carburettor, conduit 8, valvefF, conduit 9, valve 1', conthe control of the inlet valve at the move- 'llilit just described, as: the opening angle of 1 11-10 'duit 10, valve H, conduit 11', valve G and conduit 12'antl delivers it through: the outlet valve A. It is not necessary to adjust ing of the cam for. the working space inlet 7 valves ought evidently to takepla'ce for the reversing in order that the sucking inffoi" the going backwards begins at the correct inoinent. i

at rest. For tor-ward rotation without and with m en-loading and forback'ward rotation In the operations which have been d'escribed the valves G'a-nd H have remained without over-loading these valves might consequently be suppressed andxsimple pipe connectionsmight be substituted for the I same. These valves are required? forback- C ward rotation with over-loading as can be seen from Fig. 7. i

For reversing from forward rotation with over-loading to backward rotation withoverloading all the valves are required.

By adjusting the valve F the condition for the forward rotation without overloading is at first established, whereupon, by rotating the valves E through 45 and the'valves K through 180, and reversing the switch S at the same time, the condition as shown in Fig. 6 for backward rotation without everloading is established in which the engine is at first stopped by the air flowing out of the reservoir D through the valve R and then brought to backward rotation.

The ignition can 110w be reestablished so that the engine is driven again from the working space, but in reverse direction. With this object in view the switch S is brought from the position shown in Fig. 7 into the middle position so that, simultaneously with the switching in of the ignition, the two valves R and R are liberated and act consequently as check valves. The valves G and H are then brought into the position shown in Fig. 7. In this position the compressor sucks fuel and air mixture in from the carburettor V through conduit 8, valve F, conduit 9, valve 1, conduit 10, valve H, conduit 5 and the compressor valve and delivers it through the other compressor valve S, conduit 4, valve G and conduit 12 compressed according to the position of the cylinder inlet valves, to the working space of the same cylinder or through conduit l, valve G, intermediate conduit 19, valve G of the other cylinder and conduit 12 01' the other cylinder to the working space of this other cylinder, two cylinder volumes of fuelair-mixture being supplied, in the four stroke cycle engine, to the working space of each cylinder at the suction stroke of the piston.

The same reversing mechanismcould also be employed as it is for the two cycle engine, some valves being however omitted.

Evidently care has to be taken in a reversing mechanism of this type that the ignition magnet and the water and oil pumps can run to the right and to the left or can be coupled or uncoupled automatically, separate magnets and pumps working on backward rotation being provided.

The engine will, at the moment of the re versing, never be at the dead center position it it comprises at least six cylinders or four cylinders in V shape. If an engine with a lower number of cylinders should, at the reversing remain in the dead center position, a starting in opposite direction can take placeto go over into the original direction of rotation.

The reversing mechanism may evidently be utilized also as starter in both directions.

casting metal under pressure.

ly high etllciencies, but for normal eliiciencies, the average compression pressure and consequently the explosion pressure may, on account of the over-dimensioning of its cylinders, be kept lower than is possible in other engines with normal efficiency. The pie-compression pressure is then utilized, as mentioned above, merely for the complete filling of the working space within the time at disposal. In this case the strongly loaded elements of the engine, for instance the cylinders, can also be made by the process of lVhen the engine works as a two stroke cycle engine the crank cases may be turther utilized as C-Olllpressors in order to produce the required scavenging air so that, in this case, the compresssion spaces of the cylinders are again at disposal for the filling proper ot' the working space.

The piston rod 6 of the engine has, as can be seen from Figs. 1, and 1 passages 6 e, at two points. The piston rod and the pisston (Z are hollow. From the orifice of passage c a tubular conduit arranged in the hollow piston rod leads into the hollow piston, a second tubular conduit, also situated in the hollow piston, leads from the hollow piston to the orifice of passage 6 of the piston rod. The orifices of the passages e, are close to the piston (Z and those are close to the piston g. As soon as the pistons (Z move away from one another and produce consequently a pressure in the compression spaces situated between the pistons (Z and the partitions f, compressed air flows from the con'ipression space into the hollow piston wherein air, having flown along the piston walls, flows out through the tubular conduit leading to the orifice of passage 6 and into the compression space which is situated be tween the partition 7 and the piston g. The

piston 9 produces in the said space a pressure below the atmospheric when the piston (Z producesin the adjacent compression space a pressure above atmospheric.

I claim 2 1. In an internal combustion engine, a working cylinder closed at both ends, a piston in said cylinder, the space at one end of said cylinder serving as combustion chamber and the space at the other end of said cylinder serving as compression chamber, a crosshead in the form of a piston connected with said first named piston, a compression cylintl U lUU

iii;

der for saidv crosshead piston, an inlet port I for saicl: combustion chamber, outlets-for said.

compression chambers, anda common conduit connecting said outlets to said inlet port.

2. Inan internal combustion engine, a

v working cylinderclosed at both ends, a piston ii said cylinder, the space at one end of said cylinder serving as combustion chamber and the space at the other end of said" cylinder serving as compression chamber, a crosshead in the form of a piston connected with said, first named piston, a compression cylinder for said crosshead piston, the compres'sion strokes of said pistons alternating,

an inlet port for said COmbHStiOii chamber,

outlets for said compression chambers, and

a commonconduit connecting said outlets to said inlet port. 7

3. Structure"according to claim 1, wherein a piston is interposed between the two named pistons and connected therewith,-a closed cylinder for said third piston whereby a double acting compressor unit is formech and connecting means between said unit and said" inlet port. 7 r 7 r 4'. In an, internal combustion engine, aplurality of closed cylinder element-s, interconnectedpistons working in said cylinder elements, the adjacent cues of said ylinders forming compression chambers, and the opposite end of one of said cylinders forming a combustion chamber, an inlet port for said combustion chamber, outlets for said compression chambers, a common conduit .con-

iecting said outlets to said, inlet port, and means for providing communication between the adjacent ends of said cylinders, for the purpose described. i

5. Structure according to claim'l, wherein regulating means are inserted in said com munication means. U r

6. Structure according .to claim 4, wherein regulatingmeans'are inserted in said communication means, and means operable in dependence on a pressurefactor for controlling 8. Structure according to claim 4,-wherei'nregulating means are insertedin said com munication means, means operablein dependence'on the pressure in the connecting means between said compression chambers and combustion chamber-for controlling; said regulating means, and a check valve for protecting said controlling means from abnormal pressures in said last named connecting means 19.'In an internal combustionengine, a

working and compression"piston, closed cylinder therefor forniiiigcombustionand compression chamber-man inlet poit for the combustion chamber, means connecting the compressionchamber with said port, an inlet control valve for said compression chamber, and operating means for said valvecoinfpi'is ing a pair of cams, said cams being adjustab'lerelativeto each other for regulating the open period of said valve.

10. 111 an internal combustion engine, a

working cylinder closed at both ends, a piston in said cylinder, the space atone end of said cylinder servingas combustion chamber and the space at the otherfend of said cylinder serving asco npression chamber,across-- head inthe iormof a piston and connected w th said lllSiJ na i'iedpiston, a compression cylinder for said crossheadpiston, a passagef way leading to said combustion chamber,

ports connecting said compression chambers to said passageway and lyings de by s de, and a rotary outlet valve common to both or said ports. p

11. In an internal combustion engine, a

ing said cylinder into combustion and com pression chambers, a reservoir, communicating means between said compression chamber and said reservoir, and control means in said COIIiiIlLiIllOfltlIlg means, whereby, the ignition devices of the combustion chamber being rendered inoperative, said control means areoperable for admitting thejpressure or" said reservoir in said cylinder counter-to the movement of said piston for re ,versing the engine. 12. 111 an internal combustionbngme;a cylinder closed at both ends, a piston (livid ing said cylinder into combustionand 001m i ill) cylinder closed at both endspa piston divid pression chambers, a reservoir, communicat ing means between said compression chamber and said reservoir, control means in sa d communicating means, whereby, the ignition devices of the combustion chamber being rendered inoperative, said control means, are

operable for admitting the pressure of said reservoir in said cylinder counter to the movement ofsaid piston for reversing the engine, a conduit between said reservoir and said combustion,chamber, and a carburetor connectible with said reservoir,throughsai compression chamber.

13.'An explosion engine comprising in combination a working cylinder closed at both sides and worki'ngat' one end as compressor, a crosshead constructed as'second compressor piston; a cylinder-"therefor, inlet valves for theworking space, and a common conduit leading to; said inlet valves, the

compressor charges from the co npr'essorside of the working cylinder as well as from the crosshead piston cylinder being delivered to said common conduit-,wadmission conduits and; exhaust conduits for "the v compressor spaces, a reservoir for compressed air connected with said conduit, regulating elements in said conduits, the air pressure of said reservoir filled "from said compressors being adapted to act upon said compressor pistons whereby, the ignition in the Working space being at the same time cut out, the reversal of said engine is efi'ected.

14, An explosion engine comprising in combination a working cylinder closed at both sides and working at one end as com presser, a crosshead constructed as second compressor piston, a cylinder therefor, inlet valves for the working space, and a common conduit leading to said inlet valves, the compressor charges from the compressor side of the working cylinder as well as from the crosshead piston cylinder being delivered to said common conduit, admission conduits and exhaust conduits for the compressor spaces, a reservoir for compressed air con-' uected with said conduits, regulating ele ments in said conduits, so that the air pressure of said reservoir filled from said compressors is adapted to act upon said compressor pistons whereby, the ignition in the working space being at the same time out out, the reversal of said engine is effected, admission conduits for the working spaces, and regulating elements in said admission conduits whereby the gas-air mixture compressed in the cylinder compressors is admissible to the working space for the reverse operation of the engine.

15. In combination with the device set forth in claim 10, an engine shaft connected to said piston and said crosshead, valves for said combustion chamber, and a common camshaft for operating said rotary outlet valve and said combustion chamber valves.

The foregoing specification signed at Berlin this 27th day of February, 1925.

SVEN LINDEQUIST. 

